1. Field of the Invention
The present invention relates to a windshield wiper apparatus for a vehicle, and more particularly to a windshield wiper apparatus for a vehicle equipped with a rise-up mechanism for moving a wiper arm and a blade further downwardly of their lower reversing position so as to stop and accommodate the same.
2. Description of the Related Art
Among the types of windshield wiper apparatus for vehicles, a type is known which is equipped with a so-called rise-up mechanism whereby a wiper arm and a blade are moved further downwardly of their lower reversing position and stopped in order to be accommodated in a cowl box disposed below a lower end of a windshield at the time of stopping the wiper apparatus.
With the windshield wiper apparatus of this type, the wiper arm and blade are rotatably supported by a pivot shaft, and a pivot lever is secured to the pivot shaft. A link rod connected to a crank arm of a wiper motor is connected to the pivot lever, and the driving force of the wiper motor is arranged to be transmitted to the pivot lever by means of the link rod.
During the normal operation of the wiper apparatus, the torque of the wiper motor is transmitted to the pivot lever via the link rod, whereby the pivot shaft is reciprocally rotated so as to cause the wiper arm and blade to rotate reciprocally. Meanwhile, when the wiper arm and blade are to be stored, by changing the effective pitch of the crank arm of the wiper motor by the use of an eccentric pin and an eccentric shaft or the retraction and extension of the crank arm, or by changing the angle of rotation of the crank arm of the wiper motor by controlling the wiper motor itself, the pivot lever is moved further by a predetermined angle than at the time of the normal operation, thereby moving the wiper arm and blade further downwardly of their lower reversing position to a retracted position to stop and store the same.
However, with the conventional wiper apparatus equipped with such a conventional rise-up mechanism, the mechanisms of the eccentric pin, the eccentric shaft, etc., for causing the wiper arm and blade to be retracted for stopping and storage are complicated, and special components such as a motor controller and a rotation angle detecting sensor have been essential. For this reason, the overall cost of the apparatus has been high, and there has been a drawback in that a general motor cannot be used as a wiper motor.